All that is Solid … is a radical blog that seeks to promote a future beyond capital's social universe. "All that is solid melts into air" (Karl Marx and Friedrich Engels, 'The Communist Manifesto', 1848).

The French philosopher Daniel Bensaïd, who has died aged 63 of cancer, was one of the most gifted Marxist intellectuals of his generation. In 1968, together with Daniel Cohn-Bendit, he helped to form the Mouvement du 22 Mars (the 22 March Movement), the organisation that helped to detonate the uprising that shook France in May and June of that year. Bensaïd was at his best explaining ideas to large crowds of students and workers. He could hold an audience spellbound, as I witnessed in his native Toulouse in 1969, when we shared a platform at a rally of 10,000 people to support Alain Krivine, one of the leaders of the uprising, in his presidential campaign, standing for the Ligue Communiste Révolutionnaire (LCR).

Bensaïd’s penetrating analysis was never presented in a patronising way, whatever the composition of the audience. His ideas derived from classical Marxism – Marx, Lenin, Trotsky, Rosa Luxemburg, as was typical in those days – but his way of looking at and presenting them was his own. His philosophical and political writings have a lyrical ring – at particularly tedious central committee meetings, he could often be seen immersed in Proust – and resist easy translation into English.

As a leader of the LCR and the Fourth International, to which it was affiliated, Bensaïd travelled a great deal to South America, especially Brazil, and played an important part in helping to organise the Workers Party (PT) currently in power there under President Luiz Inácio Lula da Silva. An imprudent sexual encounter shortened Bensaïd’s life. He contracted Aids and, for the last 16 years, was dependent on the drugs that kept him going, with fatal side-effects: a cancer that finally killed him.

Physically, he became a shadow of his former self, but the intellect was not affected and he produced more than a dozen books on politics and philosophy. He wrote of his Jewishness and that of many other comrades and how this had never led him, or most of them, to follow the path of a blind and unthinking Zionism. He disliked identity politics and his last two books – Fragments Mécréants (An Unbeliever’s Discourse, 2005) and Eloge de la Politique Profane (In Praise of Secular Politics, 2008) – explained how this had become a substitute for serious critical thought.

He was France’s leading Marxist public intellectual, much in demand on talkshows and writing essays and reviews in Le Monde and Libération. At a time when a large section of the French intelligentsia had shifted its terrain and embraced neoliberalism, Bensaïd remained steadfast, but without a trace of dogma. Even in the 1960s he had avoided leftwing cliches and thought creatively, often questioning the verities of the far left.

He was schooled at the lycées Bellevue and Fermat in Toulouse, but the formative influence was that of his parents and their milieu. His father, Haim Bensaïd, was a Sephardic Jew from a poor family in Algeria and moved from Mascara to Oran, where he got a job as a waiter in a cafe, but soon discovered his real vocation. He trained as a boxer, becoming the welterweight champion of north Africa.

Daniel’s mother, Marthe Starck, was a strong and energetic Frenchwoman from a working-class family in Blois, central France. At 18 she moved to Oran. She met the boxer and fell in love. The French colons were shocked and tried hard to persuade her not to marry a Jew. She was bound to get VD and have abnormal children, they said.

With France occupied by the Germans and a bulk of the country’s elite in collaborationist mode with its capital at Vichy, the French colonial administration fell into line. As a Jew, Daniel’s father was arrested, but he managed to escape from the PoW camp, and rashly decided to go to Toulouse, where Marthe helped him obtain false papers. Armed with a new identity, he bought a bistro, Le Bar des Amis. Unlike his two brothers, who were killed during the occupation, he survived, thanks largely to his wife, who had an official Vichy certificate stating her “non-membership of the Jewish race”.

In his affecting memoir, Une Lente Impatience (2004), Daniel noted that these barbarities had taken place on French soil only a few decades prior to 1968. Le Bar des Amis, he wrote, was a cosmopolitan location frequented by Spanish refugees, Italian antifascists, former resistance fighters and a variety of workers, with the local Communist party branch holding its meetings there too. Given his mother’s fierce republican and Jacobin views (when a relative, after a French television programme on the British monarchy, expressed doubts about the guillotining of Louis XVI and Marie Antoinette, Marthe did not speak to her for 10 years), it would have been odd if young Bensaïd had become a monarchist.

Angered by the massacre of Algerians at the Métro Charonne in 1961 (ordered by Maurice Papon, chief of police and a former Nazi collaborator), he joined the Union of Communist Students, but soon became irritated by party orthodoxy and joined a left opposition within the union organised by Henri Weber (currently a Socialist party senator in the upper house) and Alain Krivine. The Cuban revolution and Che Guevara’s odyssey did the rest. The dissidents were expelled from the party in 1966.

That same year, Bensaïd was admitted to the Ecole Normale Supérieure in Saint-Cloud and moved to Paris. Here he helped found the Jeunesse Communiste Révolutionnaire (JCR), young dissidents inspired by Guevara and Trotsky, which later morphed into the LCR.

The last time I met him, a few years ago, in his favourite cafe in Paris’s Latin Quarter, he was in full flow. The disease had not sapped his will to live or to think. Politics was his lifeblood. We talked about social unrest in France and whether it would be enough to bring about serious change. He shrugged his shoulders. “Perhaps not in our lifetimes, but we carry on fighting. What else is there to do?”